Solid Hardwood, Engineered and Laminate Flooring - laminate flooring

We have just evicted our renters and have repairs to be done. We want to fix up the house for resale as a mountain vacation home and need to replace all the flooring. We thought laminate would be the best for longevity and easy upkeep. Do we have to have the floors level before installing? This is an older home that has had additions and goes from hardwood to plywood in the middle of a room.

The floor should be smooth and level. Look at the directions and it should tell you. Some are 1/8" within 10' -- give or take.

So how do we go about getting it level?

The issue is flat, not level.
A floor which is 6 inches higher on one side of the room can have a floor fine. It will look stupid but will work fine.
As long as it is flat with no great deviations under it which cause gaps under a stiff board or make a row not line up. That would make sqweaks and pops when the wood flexed and did not hit a flat surface instantaneously.
The way to flatten a floor is going to vary with the subfloor.
Do a search below on the word FLAT and you will find the techniques described in excruciating detail